Switch lock



H. B. AUSTIN SWITCH LOCK Filed 001;. 26, 1928 2 Sheets-Sheet l Patented ot. 2?, 19 31 sire s'rATEs PATENT OFFICE HARVEY B. AUSTIN, OF VJAYNE, PENNSYLVANIA, ASSIGNOR TO THE PRINGLE ELEC- TRIGAL EANUFACTUEENG COMPANY, 03; PHILADELPHIA,

POBATIGN CF .PEZEZQ'SYLVANIA PENNSYLVANIA, A COR- SWITOI-I LOCK Application filed October 26, 1928.

My invention relates to knife switches that may be subJected to abnormally heavy currents with the stresses tending to burst open the switches that are incident to such currents.

f A purpose of my invention is to provide novel and inexpensive means for adapting a closed switch blade to stay closed if subjected to the heavy opening stresses incident to any abnormally high current through the switch, means that will not prevent the easy opening and closure ofthe switch by an operator and that will be operated automatically by such opening and closure.

A further purpose is to make the initial outward pull upon the pull-ring of a switch blade operate a release for oppositely directed lateral locks that when not released are adapted to hold the switch closed against the opening stresses that are incident to any abnormally high current through the switch.

further purpose is to start the opening movement of a switch blade by the aid of a movable member that is first used to release a lock holding the blade shut.

A further purpose is to make the opening movement of a switch blade laterally retra'ct a lock that has been first released by the opening pull on a pull-ring of the blade.

A further purpose is to definitely look a switch lock in its receiving position by means of the outward movement of the switch blade and of a cooperating member following the blade, the follower member moving to a position across the lock.

A further purpose is to use the closing movement of a switch blade to release a lock member operated within a stationary abutment at the side of theclosing blade and to wedge the lock part way out of the abutment into a lateral recess of the blade when the blade closes, using a spring-pressed wedge member back of the lock to move the lock into its locking position and to normally block it from opening movement.

A further purpose is to lock aswitch blade in 'closed position by means of ball members, preferably of hard steel, upon opposite sides of the blade and each extending part way into the blade and part way into a stationary Serial No. 315,214.

structure at the side of the outer end of the closed blade.

A further purpose is to provide the outer end of a switch blade with hard recess bearings for lock members that enter the blade from stationary side abutments when the blade closes. I may form thesebearings as the recessed ends of a hard pin set transversely through thethickness of the blade end or may provide the blade with a hard metal extension beyond the jaw contacts of the switch, re'cessing the extension member upon opposite sides to provide the bearings.

A further purpose is to look a switch blade in closed position by means of ball members upon opposite sides of the end of the blade, each when inlocking position extending part way into the blade and part way into stationary structure along side of the blade and each having a diameter greater than the thickness of the blade and greater than the distance between the opposing faces of the structure housing the ball members.

A further purpose is to relieve the locking portion of a switch blade from the efiect of hammer blows incident to repeated closures of the switch.

A further purpose is to provide an inexpensive and desirable form of pull ring that is mounted upon the end of a switch blade and that is adapted to operate a switch lock release wiien pulled to open the switch blade.

Further purposes will appear in the specification and in the claims.

I have elected to show two only of the different forms of my invention, showing however min-or modifications and selecting forms that are practical and eilioient in operation and which well illustrate the principles involved.

Figure 1 is a side elevation of switch structure embodying one of the desirable forms of my invention, the switch blade being shown full line in closed position and in dotand-dash line in raised position, and a dotand-dash indication being given that the switch may be double-throw if desired.

Figure :2 is a top plan view of structure shown in Figure 1.

Figure 3 is a section taken upon the line 33 of Figure l. I Figure 4 is a'view corresponding to Figures 3 but showing the parts in somewhat different positions, those which they occupy when the pull ring is defiectedpreparatory to opening the switch.

Figure 5 is a view corresponding to Figures 3 and 4 but with the parts in difierent positions those which theyo'ccupy when the 'sirable formof blade QIKllDCk 'Wlbll the blade in closed position.

IFigure 9 isa section taken upon the line 9,9of'Figure"8.

- -.Figure 10 is. an end view of structure shown in Figure9. x

"Likeg numerals refer tolikeparts in all figures. 4

Describing in illustration and. not in limitation and referring to the drawings p My invention is more particularly for use with switches forv electric mains.

These switchesmay-at times through ac cident or otherwise have to carry extremely heavy currentsand my invention is directed at a safety device for preventing the auto. matic bursting open of'a switch in the event that the switch is at any time subjected to abnormally heavy current.

The terminal 13 carries the usualspa'ced hinge contacts-15 and 16, which are plates suitably slotted at'17 into the base plate. The switch blade 19-is hinged at 18 between the hinge contacts which press flat against opposite sides of the blade. V Corresponding plates 20 and 21 mounted uponthegtermina'l 14 are .the usual spaced jaw contacts that receive the outer, end of the blade when the switch is closed. I

The blade 19 when closed extends out beyond the receiving contacts 20 and21 and carries a pull-ring 22 for use in opening and closing the switch.

The pull-ring operates beyond the end of the blade in the plane of the blade but is thicker than the blade and bifurcated at 23 to provide rearwardlyextending side plates 2tthat'in the form illustrated in Figures 3 to 5 are pivoted to the blade at 25 and rearthe bore 38.

wardly extended to support between them a pin member 26Qthat includes lateral extensions 27 upon opposite sides of the blade and an intermediate body 28 between the side plates and in a perforation 29 through the blade.

The laterally extending'portions 27 may desirably be of less diameter than the body portion and serve to release the switch lock when the pull-ring is pulled'or pushed in a direction to open the switch. 2

The range of angular movement of the pull-ring rocker may be determined by engagements between the body portion 28 and the opposite sides of the perforation 29 through the blade, or by engagements. between the intermediate portion 22 of the ring andthe extreme end of the blade. 7

The side plate portions 2a of the pull-ring may desirably be made initially separate from the ring to which they may be suitably fastened as bypins 30. V

I mount a hard metal disc 31 transversely through the blade at a positionoifset from the perforation 29 and longitudinally recess the disc at each end.

When the blade is closed the recesses in the opposite ends of the disc 31 receive the projecting portions of lock members 32 that operate in a stationary housing structure 33.

Desirably the lock members 32 are hard steel balls and the discinsert 31 may also desirably be of-hard steel. V V

. The housing member 33 is mounted on the terminal plate'lt across the outerends of the contactplates 20 and 21 beingfastened to the terminal plate by screws 34 through suitable lugs 35, v

The housing member is slotted at 36 to receive the switch blade to a depth beyond the end-recesses in the disc 31 when the blade is closed the bottom of the slot optionally forming a stop that definitely determines the closed position ofv the blade.

The housing member portions 37 on opposite sides of the slot 36 are bored at 38 to receive the lock members 32, the alinement of the bore being perpendicular to the plane of'the blade movement and its position that to register when the blade is closed, with the recesses in the endsfof the insert member 31 carried on the outer end of the blade.

The lock members 32. are positively and variantly limited in their outward positions by pin members The pins 39 areslidably mounted in guiding holes 40 across the bore 38'so as-to be across the outwardly presented surfaces of the lock members 32 and variantly and positively limit the outward position of the lock members according to the longitudinal positions of the pins.

Each pin 39 is cut flat on the side toward the blade for some distance from its outer 39 that operate square across end'at 41 and then tapered outwardly at 42 to full diameter, and the outer ends of the guiding bores 40 are given a contour at 43 to fit the outer noncircular portion of the pm.

The pins 39 are shown with narrow stems 44 that suitably limit the downward movement of the upper ends of the pins so that these ends may not be pushed down into the bore beyond the noncircular portion 43. These stems .44 preferably engage the surface of the terminal before the pull-ring lever has come to the end of its range of travel so that the initial pull upon the pullring starts the opening movement of the switch by prying engagement between the pins 27 and the tops of the lock release members .39.

As illustrated, springs 45 surround the stems are compressed between the outwardly directed surface of the terminal member 14 and the inner ends of the pins 39 so that the pins are resiliently pressed outwa dly by the springs.

The flat portions 41 of the pins are in positions to engage the lock members to limit the outward positions of the lock members.

When the pins 39 are depressed their flats 41 extend across the outsides of the respective balls 32 which are then free to occupy a position far enough outwardly to permit passage of the knife blade between the opposing balls.

If the pin members 39 are in their upper positions the full diameter sections of the rods are presented to the outer sides of the lockmembers 32, and the lock members must occupy positions in which they extend inwardly into the path of the switch blade.

- If the switch blade be already closed during the upward movement of the pins 39, the lock members are pressed by the wedge surfaces 42 into the respective recessed ends of the insert member 31 and lock the blade with respect to the casing member, in that the balls or other lock members are positively held by the pins from moving outwardly.

The switch lade cannot open unless the lock members 32 are free to be displaced out wardly from the recesses in the ends of the inset member 31, and therefore cannot open unless the pins 09 are suitably depressed.

l Vhen the blade is opening it pushes back the lock members, separating the lock members by the thickness of the blade, and I provide a blade follower member 46 that resiliently follows the blade until left in a position between the lock members 32.

When the switch blade is closing its inner edge engages the member 46, which is then blocking the lock members apart, and pushes the member inwardly out of the way, the member 46 resiliently pressing against the inner edge of the switch blade as long as the blade is closed.

hen the blade is opening the member 46 follows the blade outwardly until it replaces the blade in blocking the members 32 apart in their receiving positions.

The follower member 46 is slidably mountin a bore 47 and counterbore 48 in the intermediate portion 49 of the housing structure and part way through the terminal plate 14.

The head 50 of the follower member fits the counterbore and limits the outward position of the member and a spring 51 outwardly presses the member toward its outer position, that in which its upper end blocks the lock members apart.

The thickness of the body of the follower member is preferably substantially the same as that of the blade.

When the lateral rods 39 move, their inner faces slide against the outer sides of the lock members.

If the lock members are in their outer positions the lateral pin members must be in their depressed positions and if the lock members are definitely blocked by the upper end of the follower member 43 from moving inwardly from their outer positions the lateral rods cannot move up to a position that pushes the lock members inwardly.

The housing member 33 is desirably an integral block slotted in front of the blade and having the bore that cases anc. guides the member 46 in the plane of the switch'blade and perpendicular to its length when the blade is in closed position, and the bores that case and guide the members 39 parallel to the plane of the blade, and preferably though not necessarily perpendicular to the length of the blade.

in operation and starting with the switch tion presenting tl' eir flat portions to theouter sides. of the lock members 32, the lock members being out in their receiving position.

While the switch is being closed, the forward edge of the switch at 52 engages the nter end of the follower member 46 pushc. the follower member ahead of it until the blade stops against the bottom of the slot and is in its closed position.

In this position the recesses in the ends of the disc insert 26 register with the inner sides of the lock members 32, leaving the lock members free from support against their inner sides.

F or the lock members I select sliding or rolling members each having sloping end surfaces adapted to cooperate with and inlt-aneously engage the sloping surfaces of the disc 31 and the surfaces of the adjacent pin 39.

Because these end surfaces are obtainable in a very suitable andcheap" form in the hardened steel balls of commerce, I prefer to use these balls and because the purpose is best served by a compact structure, I prefer to use a single ball rather than a row of two or more balls between the pin 39 and the socket hearing in the blade, preferring one ball on each side of the blade that engages the blade on one side and the pin 39 on the other.

i I also prefer to use a single ball rather thana plurality of balls between the blade 19 andthe pin 39, because this means ball locks of larger diameter and I'find it desirable to have the ball diameter too great for possibility of the ball escaping into the slot 36.

I I have found that the individual hard steel balls, one upon each side of the'blade and of diameter greater than the width of the slot 36, make an inexpensive, and very eficient form of lock.

As soon as the recesses'in the ends of the disc insert 26 register with the inner ends of the lock members 32, that is, as soon as the switch blade closes, the springs 45 underneath the rods 39 liftthe rods 39 which thereby wedge the lock members into the recesses of the blade, firmly blocking them against outward movement and thus firmly locking the blade to'the housing 33 .which is firmly fastened to the terminal 14 by the screws 34.

As a result while any abnormally high current through the switch will tend to burst the switch open, such opening is prevented by the positive looking at the members 32.

To open the switch a suitable'hook is inserted in the ring 30 and the ring is pulled outwardly which causes it initially. to-rock upon its pivot 25 causing the pin extensions 27 that register with the tops of the pins 39, to depress the pins 39 into a position at which their fiat portions 41 are opposite the lock members, leaving the lock members free to move outwardly. I Continued pull on the ring 30 mayfdesirably initially start the opening movement by prying engagement between the outer ends of the pins 39 and the pin extensions 27 and then moves the blade out from between the contact members 20, the outward movement. of the blade forcing the lock members outwardly into the recess 38. i

As the switch blade'is moving outwardly the follower member 46' follows it to a p'osition between the lock members thus blocking the lock members apart in their receiving position, the lock members in turn locking the pins 39 from moving upwardly in viewof the lack of room to permit the lock members to move inwardly. I

' During the next closure when the lock members are released'by the registry of the recesses in the blade with the inner sides of the lock members, the spring pressure upon the pins 39 moves the pins upwardly to wedge the lock members into their locking position and definitely locks them in this position. 7 The material of the switch blade is normally copper which is itself too soft a metal for the recess bearings that receive the lock members 32. 1

The seats or bearings in opposite sides of the blade for the lock members are preferably very hard, much harder'than copper and in the figures thus far described, comprise the recessed ends of a hard metal disc 31 that is inserted through the thickness'of theblade. When the switch is, closed it must be in position for an exact registry of the recesses of the blade with the lock'members, and for this reason the blade closesagainst a definite stop. I f I y In the structure of Figures 3 to 5 the stop thatdet-ermines the position of closure comprises the upwardly directed surfaces of the casing or housing member 33 at the bottom of the slot 36 for a short distance at 53 Figure 6) longitudinally of the blade on eachside of the follower pin 46, the forward'edge of the blade, at 54 (Figure 1 orfFigure 6) coming against these surfaces at every. closure. 7

It has been suggested that if thegswitch is to be opened andclosed very frequently with very vigorous closures, the impacts between V the surfaces 53 and 54 may gradually deform the engaging metal of the blade sufiiciently to loosen the disc 31 and in'the structure of Figure 6 I have guarded against this eventu-r ality by providing a fiber stop 55 between the contact jaws 20 and 21: This stop receives the blade and deadens the impact of closure thereby avoiding any danger of deformation of the metal of the blade nearthe lock bearing member 31. Normally the fiber stop is not necessary, any deformation incident to the closure engagements between the surfaces53 and 54 being immaterially small.

I desirably chamfer the edge of the engagement surfaceof the follower member 46 at 56 in order to avoid any distortion of this surface due to its repeated, engagement with the switch when the vswitch is closing. Desirably too, the follower member'may be hardene In Figures 1 to 5 I have illustrated the pull-ring 22 ascomposite with a pin portion 26 that extends through a suitable perforation 29 in the blade. r

In some cases I may prefer to make the pull-ring an integral casting and'have so illustrated it in Figures 8 to 10 where the ring 22 is pivoted at 25 upon the end of the blade and the operating lateral extensions 27 do not extend inwardly through the blade but are integralextensions from the single casting that forms the ring; Either the integral form or the composite form may bev other very desirable form that avoids any dangerof blade distortion at the lock bearings incident-to closure impacts by plOVlCllIlg the end of the blade, witha hard metal extension from the copper portion, the hard metal extension tov the blade carrying the pull-ring and being laterally recessed to form the lock bearings.

The copper portion of the blade ends a little beyond the jaw contacts and 21, and presents an outwardly directed end tongue 59 fitting into a rearwardly directed groove 60 of the hard extension member 61, which is desirably steel.

The tongued and grooved joint is suitably riveted at 62, and the member 61 is laterally recessed at 63 to provide the seats for the lock members 32.

Preferably the recess bearings 63 are hardened.

The lock members may be exactly as already described but when I use this hard metal extension, desirably hard steel, I prefer to stop the blade at closure against the bottom of the slot rather than against fiber material inserted between the jaw contacts.

I preferably rearwardly extend the stop ping surfaces 53 so as to overlap and engage the end of the copper portion of the blade as well as the rearward edge of the extension piece, in order to eliminate or lessen stresses upon the joint incident to any hammer blows of unnecessarily vigorous switch closure.

In view of my invention and disclosure variations and modifications to meet individual whim or particular need will doubtless become evident to others skilled in the art, to

obtain all or part of the benefits of my invention without copying the structure shown, and I, therefore, claim all such in so far as they fall within the reasonable spirit and 50. scope of my invention.

I near its movable end, a

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A switch blade recessed on opposite sides pull ring movably mounted on theend of the blade, stationary abut-ments having opposing faces in positions respectively adjacent opposite sides of the blade end when the blade is closed, lock members having stationary bearing support upon opposite sides of the switch in the abutments and means operative by closure of the blade for moving the lock members partially out of their bearings laterally intothe recesses in the switch blade.

2. A switch blade recessed on opposite sides near the movable end, a pull-ring movablymounted on the blade, stationary abutments having opposing faces in positions respectively adjacent opposite sides of the blade end when the blade is closed, lock members having stationary bearing support upon opposite sides of the switch in the abutments and means operative by closure of the blade for moving and locking the lock members partially out of their bearings laterally into, the recesses in the switch blade.

is switch blade recessed on opposite. sides near the movable end, a pul1-ring'InOVa-bly mounted on the blade, stationary abutments ha ingoppesing: faces positionsre pectively adjacent opposite sides of, the blade and when the, blade is closed, hard balls having stationary bearing support upon opposite sides of the switch in the; abutments and means. operative by closure of the blade, for moving and locking the balls. partially out of their bearings laterally into the; recesses in the switch blade.

4. In a switch,ablade having recesses upon opposite sides of its movable end, stationary laterally extending bearings in positionsv to. register respectively with the. recesses, lock members in the bearingsadapted to partially enter the recesses when the switch is closed,

mechanism for locking the lock members.

from moving out of the recesses and a release for the mechanism operated by the operation of the pull-ring when. pulled to open the switch.

5. In a switch lock for a switch blade, a lock adapted to fasten the blade shut when the switch blade is closed and a pull-ring pivotally mounted upon the end of the blade for opening and closing the switch, a release member-mounted: off the blade and having an inner and an outer position and adapted to release the look when moved from its outer to its inner position, means limiting the inward movement of the release member adapting it to support an opening pry of the pull ring upon the blade, and connections between the release member and the pull-ring adapting the pull-ring when pulled in a direction to open the switch to first release the lock and then to exert an opening pry upon the blade by reason of its engagement with the release member.

6. In a switch look, a switch blade, a laterally directed stationary loclr-bearing in position adjacent a side of the movable end of the blade when the blade is in closed position, a lock in the bearing adapted to laterally engage and hold the blade when the blade is in closed position and to open when the switch opens, in combination with a blade follower member movable in the resiliently engaging the blade-when the blade is in closed position and following the blade outwardly when the blade is opening to a plane of the blade,

7 position at which it blocks the switch lock open. 1 7; In aswitch, a switch lock open when the switch is open and spring pressing to-" ward closure, and amovable member fastening the lock open when the switch'is open, adapted to be engaged and retracted by the inner edge of the closing blade to permit the lock to close when the switch is closed.

8. In a lock for a switch blade having a 'lateral recess near one end of the blade, a

stationary housing member having a slot adapted to receive the movable end of the blade at the recess whenthe blade closes, a

lock bearing in the housing registering with the lateralrecess in the blade when the blade is in closed position," alock in the bearing adapted to enter'the recess to lock the blade with respect to the'housing, a lock operating member-"having bearing in the housing parallel to the plane of the blade and perpendicu-' lar to the' bearing of the lock and having wedge engagement with the outer side of the lock adapting the operating member to limit the outward position ofthezlock according tothe longitudinal position of the operating member,- a spring pressing the operating member in a direction to close the lock and a blade followermember adapted to move in the plane of the blade and spring-pressed to a position in which it blocks the locking operation of the lockland adapted to be engaged and retracted bythe closing blade.

slot across'the transverse borings,

9. In a lock for senting a slot to receive the blade and bored transversely to the slot at-right angles tothe plane of the blade, bored parallel to the and bored inthe plane ofthe blade at the bottom of the slot in-alinement'across the first boring in combination with a lock in the first boring,

I lock operating membersin the second borj j ings and'a member 'for holding the lockmembers in retracted position when the switch is open in? the third boring.

10. In a switch, hinge contacts, jaw contacts',a blade pivoted at the hinged contacts and adapted to be received by the jaw contacts, lateral locks respectively upon opposite sides of the'blade beyond the jaw contacts, an

vinset bearing for the locks mounted in the extended blade and adapted to receive the locks when the blade is closed and a stop between thevj aws for registering the blade in its closure. position by engagement with the in-' ner edge of the closing blade.

a movable switch blade, a Q 1 housing at the movable'end of the blade preclosure to register the recesses with the locks.

12. In a switch, hinged contacts, jaw contacts, a blade pivoted at thehinged contacts and adapted to be received between thejaw contacts, a'hard metal extension to the blade beyond the j awcontacts having recesses upon opposite sides, lateral locks adapted to enter the recesses when the blade is in closed position and a stop for'receiving the blade at closure to register the recesses with the locks, the stop overlapping the outer portion of the blade and the adjoining inner portion of its extension. I a

' HARVEY AUSTIN. 

